Stroke severity and other predictors of venous thromboembolism in stroke patients—a population-based cohort study

Background: Venous thromboembolism (VTE) frequently occurs after stroke, particularly within the first 3 months after diagnosis. Poststroke VTE is associated with increased mortality. Stroke severity is a known predictor of adverse prognosis; however, its ability to predict VTE is unclear. Knowledge regarding other predictors of poststroke VTE is lacking. Objectives: To identify clinical predictors of poststroke VTE in the subacute and acute phases, and to assess the association between stroke severity and poststroke VTE. Methods: In a population-based cohort study, we identified patients (aged ≥18 years and without recent VTE) with first-time ischemic stroke (N = 129,345) or intracerebral hemorrhage (N = 16,887) from 2004-2021. We computed the cumulative incidence proportion and subdistribution hazard ratio for VTE for each potential predictor in the subacute phase (3 months) and acute phase (7 days). For stroke severity, measured with the Scandinavian Stroke Scale, we calculated adjusted subdistribution hazard ratios in 2 multivariable models including (1) age and sex, and (2) predictors identified in the univariable analyses. Results: In the subacute phase, 1016 (0.8%) patients developed VTE after ischemic stroke, and 200 (1.2%) patients developed VTE after intracerebral hemorrhage. In univariable analyses, VTE risk was 2- to 5-fold higher in those with severe stroke, active cancer, and previous VTE. These findings were consistent for both stroke subtypes and follow-up periods. Multivariable analyses showed no substantial alterations in the estimates for stroke severity. Conclusion: Stroke severity, active cancer, and previous VTE strongly predict poststroke VTE in patients in the subacute and acute phases. These findings offer valuable insights and can be used to identify patients at elevated risk of VTE in whom extended thromboprophylaxis may be considered.